Batteryless pocket spark plug tester

ABSTRACT

A batteryless pocket spark plug detector operative with a piezoelectric crystal wherein the application of a compressive force to a piezo-electric crystal causes a high voltage signal to be applied across a spark plug so as to test whether there is an arc across the gap, and if not across the gap, across breaks in the insulation of the spark plug. If the latter occurs, the spark plug is defective. A neon bulb is provided for sensing the operation of the coil and, further, to indicate the operativeness of the device.

1451 Feb. 19, 1974 United States Patent [191 Maria et a1. 0

BATTERYLESS POCKET SPARK PLUG TESTER [76] Inventors: Paul Maria, 1618 Ridge Rd.,

OTHER PUBLICATIONS Gannon, Robert, Spark Pump Fires Engine, Popular Science, July 1.961, pp. 70-73 and pp, 174-175.

Perkasie, Pa. 18944; Albert Conard, Main St., Sellersville, Pa. 18960 July 21, 1972 Primary Examiner-Rudolph V. Rolinec Assistant Examiner-Rolf Hille [22] Filed:

[21] Appl. No.: 273,730

[52] US. 324/15, 310/8.7 [51] Int. Cl. G0lm 19/02, GOlr 31/00, 1-101v 7/00 a compressive force to a piezo-electric crystal causesa [58] Fleld of high voltage signal to be applied across a spark plug so 315/55; 310/81 as to test whether there is an arc across the gap, and if not across the gap, across breaks in the insulation of the spark plug. If the latter occurs, the spark plug is defective. A neon bulb is provided for sensing the operation of the coil and, further, to indicate the opere .m V e d e h. t Fl 0 S S e n Pv V n 3 x5 aw W3 Sm T m N m m W n m m wA Lm C a S u m CT ca m mm rTbM .mSE D mm n99 NHH Unn 38 21 0 m A 46 5 rl 33 324/15 4 Claims, 4 Drawing Figures 2,728,888 12/1955 Ellison..... 2,118,137

'BATTERY'LESS POC KET'SPARK PLUG TESTER BACKGROUND OF THE INVENTION In the =past,\piezo-electric devices have been utilized as a substitute for a source in internal combustion engines to energize spark plugs. Further, these sources have been utilized in hand held devices such as electric lighters to light a butane fuel. However, when it came to providing a simple spark plug tester, all such testers were rather large cumbersome devices which required that the spark plug be taken to the testing unit to be checked out. However, the average service man needed a simple unit which would allow him, while on the job, to check out each of the spark plugs to make sure that the insulation had not cracked and that the gap was in fact arcing with the application of voltage thereto. This type of device must be simple and easy to handle, extremely rugged in construction andshould not require a separate power source such as battery as such power source is inevitably run down. Further, there should be a simple means for checking operation of the spark plug tester so as to avoid false readings.

It would additionally be useful to have a system for checking for wiring and operation of the electrical system which was also hand held and could be easily transported.

SUMMARY OF THE INVENTION The invention comprises a small hand held unit about the size of apack of cigarettes with a socket thereon for receiving the base of the spark plug. The base of the spark plug is then connected to one terminal of a piezo electric device in series with a neon bulb. The other terminal of the piezo electric device is connected through a spring contact member to the side wall of the spark plug so that a circuit is completed through the spark plugin a conventional manner. A suitable spring mechanism is operative to drive a compression device against the piezo electric crystal to cause compression thereof. The compression of the piezo electric crystal causes the high voltage signal to be applied through the neon bulb to the spark plug. The lighting of the neon bulb indicates that the tester is operative.

Further, one can easily view whether there is an arc across the gap of the spark plug showing that the spark plug is operative. If there is no arc across the gap of the spark plug, then there is usually some type of arcing within the insulation of the spark plug indicating that the sparkplug is defective. This gives a quick simple check as'tothe effectiveness of the spark plug and a new spark plug can be inserted therein. It should further be noted that the neon bulb, in itself, when placed near any of the wires of the ignitition system, while the car is operating will sense the passage of current through the wires by lighting. up and, thus, the spark plug tester provides a dual purpose.

DETAILED DESCRIPTION OF THE DRAWINGS FIG. 1 is aperspective view of the spark plug tester of the present invention witha spark plug in place.

FIG. 2 is a cross sectional view of the spark plug tester of FIG. 1. I I

FIG. 3 is a partial cross sectional view of the operating mechanism for the piezo electric crystal after compression.

FIG. 4 is a schematic showing of the electric circuit of the present invention.

In FIG. 1, there is shown the spark plug tester of the present invention generally designated by the numeral '10. The spark plug tester comprises a generally rectangular case 12 made out of a hard plastic material. The case 12 has one corner thereof recessed to form an area for receiving a spark plug 14. In the recessed area 16, there is provided a suitable flat surface 18 with a socket 20 therein receiving the lowermost contact 22 of the spark plug 14. The spark plug 14, has a suitable gap 24 which is in electrical conductive relation with a metal conductive ring 26 thereabout. On the side wall 28 of the recess 16 there is positioned a conductive spring member 30. The conductive spring member 30 is connected to one terminal 32 of a piezo electric de vice 34. The other terminal 36 .of the piezo electric device 34 is connected through a neon indicator light 38 to the socket 20. The piezo electric device 34 is a device which, upon compression, causes a high voltage signal to be transmitted across its output terminals.

The piezo electric device 34 is within a tubular case 40. A striker element 42 is positioned withinthe tubular case 40 and is spring biased by way of a light spring 44 away from the electric device 34. The spring 42 forces the striker 42 backward so that a suitable latching member 46 rests on a ledge 48. On the side of the striker 42 opposite spring 44 there is a strong spring member 50 about a suitable plunger mechanism 52 connected to actuator 54. Also connected to' the plunger 52 is a camming device 56 which stops outward movement of the plunger 52. When the actuator 54 is compressed as per the arrow 58 spring 50 is compressed until such time as the camming member 56 hits latch 46, forcing it off the ledge 48 and into a groove 60. When this occurs, the force of spring 50 is released driving striker 42 against the piezo electric device 34 causing immediate compression thereof and a high voltage electric signal to be transmitted through neon bulb 38 to the spark plug 14. When the actuator 54 is released, spring 44 returns the striker 42 to its original position and twists are member 46 back onto ledge 48. Similarly, camming member 56 is returned to its original position by spring 50 and the tester is ready for another usage thereof.

- As can be seen, with each movement of the actuator 54, a high voltage pulse'signal is supplied to the spark plug 14 to check whether an arc is transmitted across its gap 24. Further, with each operation, the neon bulb 38 will be operated indicating that the tester itself is operating. If no arc appears across the gap 24, then the spark plug 14 is not operative.

Further, normally, when no arc appears across the gap 24, an are or arcs will appear across breaks in insu- Iation on the spark plug 14 further indication that the spark plug 14 is inoperative. It can be seen, easily, that it is simple to install the spark plugs 14 into position and, further, by reason of the arrangement of the spring 30 in the manner whereby it is in wiping relation with the ring 26 on a spark plug, and resiliently pivotal about contact 32, the tester 10 can accept spark plugs of varying sizes without any change. It further should be noted that the neon bulb 38 acts not only as a checker for operation of the spark plug tester, but as an independent tester for indicating signals in the wiringof the motor as the motor is running. That is, it will pick up high frequency signals from the choke and other parts of the electrical system indicating that they are operative.

Although this invention has been described with respect to its preferred embodiments, it should be understood that many variations and modifications will now be obvious to those skilled in the art, and it is preferred, therefore, that the scope of the invention be limited, not by the specific disclosure herein, only by the appended claims.

We claim:

1. A spark plug tester comprising:

a piezo electric crystal;

compression means for applying a compressive force to said piezo electric crystal; a casing adapted for holding in the hand of the user; said piezo electric crystal being mounted within said casing;

said compression means comprising a spring biased snap-action striker, said striker being mounted for quick snap action movement to strike against said piezo electric device to effect a momentary com pression ofsaid piezo electric device;

said striker being latch-mounted, spring means mounted behind said latch-mounted striker, and means for compressing said spring means and unlatching said striker to cause movement of said striker against said piezo electric device, return spring means oppositely mounted with respect to said first mentioned spring means for allowing only momentary striking of said piezo electric device and being further operative to re-latch said striker for a subsequent operation;

a socket for receiving a spark plug mounted on said casing; and

spring biasing contact means adjacent said socket on said casing for making contact with a conductive ring of a spark plug, said spring biasing contact mean being connected to one terminal of said piezo electric device and said socket being connected to the other terminal of said piezo electric device. 2. The spark plug tester of claim I includingindicating means connected in circuit relation with said piezo electric device.

3. The spark plug tester of claim 2 wherein said indieating means is a neon bulb in series with said piezo electric device.

4. The spark plug tester of claim 1 wherein said spring contact means is a spring pivotally mounted to one terminal of said piezo electric device. 

1. A spark plug tester comprising: a piezo electric crystal; compression means for applying a compressive force to said piezo electric crystal; a casing adapted for holding in the hand of the user; said piezo electric crystal being mounted within said casing; said compression means comprising a spring biased snap-action striker, said striker being mounted for quick snap-action movement to strike against said piezo electric device to effect a momentary compression of said piezo electric device; said striker being latch-mounted, spring means mounted behind said latch-mounted striker, and means for compressing said spring means and unlatching said striker to cause movement of said striker against said piezo electric device, return spring means oppositely mounted with respect to said first mentioned spring means for allowing only momentary striking of said piezo electric device and being further operative to re-latch said striker for a subsequent operation; a socket for receiving a spark plug mounted on said casing; and spring biasing contact means adjacent said socket on said casing for making contact with a conductive ring of a spark plug, said spring biasing contact mean being connected to one terminal of said piezo electric device and said socket being connected to the other terminal of said piezo electric device.
 2. The spark plug tester of claim 1 including indicating means connected in circuit relation with said piezo electric device.
 3. The spark plug tester of claim 2 wherein said indicating means is a neon bulb in series with said piezo electric device.
 4. The spark plug tester of claim 1 wherein said spring contact means is a spring pivotally mounted to one terminal of said piezo electric device. 